(February 20, 2012) Legendary American tennis coach Brad Gilbert, who coached Andre Agassi and Andy Roddick each to Grand Slam titles and the No. 1 ranking, and helped guide Andy Murray and Kei Nishikori to their current elevated ATP rankings, has agreed to work on a trial basis with Sam Querrey starting immediately.

The official news was broken by Zoo Tennis' Collette Lewis last week.

Apparently Gilbert, who most recently maintained a part-time limited-travel relationship with Japan's Kei Nishikori while Dante Bottini functioned as his primary coach, will maintain the same type of role in the Querrey camp.

Querrey, who stood at world No. 17 just over a year ago, has dropped to No. 99 this week while trying to recover from a prolonged absence after an elbow surgery last season.

Querrey decided to part ways with his long-time coach David Nainkin recently.

For Querrey, who has all the tools but lacks the patience to employ them at times, a relationship with Gilbert, who is known for preaching tactical awareness, mental toughness and "winning ugly" could be his ticket back to the top 20.